Leadership for Policy Change

Provides options for utilizing foundation and government support to create and enhance community-based leadership development programs in communities of color

Characterization of an 8-cm Diameter Ion Source System

Results of tests characterizing an 8-cm diameter ion source are presented. The tests were conducted in three separate vacuum test facilities at the University of Alabama-Huntsville, Colorado State University, and L3 Communications' ETI division. Standard ion optics tests describing electron backstreaming and total-voltage-limited impingement current behavior as a function of beam current were used as guidelines for selecting operating conditions where more detailed ion beam measurements were performed. The ion beam was profiled using an in-vacuum actuating probe system to determine the total ion current density and the ion charge state distribution variation across the face of the ion source. Both current density and ExB probes were utilized. The ion current density data were used to obtain integrated beam current, beam flatness parameters, and general beam profile shapes. The ExB probe data were used to determine the ratio of doubly to singly charged ion current. The ion beam profile tests were performed at over six different operating points that spanned the expected operating range of the DAWN thrusters being developed at L3. The characterization tests described herein reveal that the 8-cm ion source is suitable for use in (a) validating plasma diagnostic equipment, (b) xenon ion sputtering and etching studies of spacecraft materials, (c) plasma physics research, and (d) the study of ion thruster optics at varying conditions

Knowledge About the Human Papillomavirus Vaccine Among Employees at a Tertiary Cancer Center: Room for Improvement

Introduction: The human papillomavirus (HPV) vaccine is recommended by the U.S. Centers for Disease Control and Prevention for routine vaccination of boys and girls to protect against HPV-related cancers and genital warts. To meet the Healthy People 2020 target for HPV vaccination, health care providers must understand the importance of strongly recommending the HPV vaccine to all eligible adolescents. We sought to determine HPV vaccination patterns among employees at a tertiary cancer center and their children and attitudes regarding HPV vaccination among the employees. Methods: All employees at a tertiary cancer center were invited to participate in a cross-sectional survey administered online during July and August 2015. The survey included questions about HPV vaccination of participants and their children, including reasons why vaccine-eligible employees and children had not been vaccinated. Results: Of those eligible, 13% of male and 33% of female employees and 44% of daughters and 24% of sons of employees had completed the vaccine series. The main reasons for not completing the series or not having one’s son completing the series were not knowing that the vaccine was needed and vaccine not recommended by a health care provider. The main reasons for not having one’s daughter complete the series were the two aforementioned reasons and daughter not yet sexually active. Conclusion: Opportunities exist to educate health care workers about the benefits of the HPV vaccine and to increase the number of providers who recommend HPV vaccination to their patients

Constant amplitude and post-overload fatigue crack growth behavior in PM aluminum alloy AA 8009

A recently developed, rapidly solidified, powder metallurgy, dispersion strengthened aluminum alloy, AA 8009, was fatigue tested at room temperature in lab air. Constant amplitude/constant delta kappa and single spike overload conditions were examined. High fatigue crack growth rates and low crack closure levels compared to typical ingot metallurgy aluminum alloys were observed. It was proposed that minimal crack roughness, crack path deflection, and limited slip reversibility, resulting from ultra-fine microstructure, were responsible for the relatively poor da/dN-delta kappa performance of AA 8009 as compared to that of typical IM aluminum alloys

Mixing of Supersonic Streams

The Strutjet approach to Rocket Based Combined Cycle (RBCC) propulsion depends upon fuel-rich flows from the rocket nozzles and turbine exhaust products mixing with the ingested air for successful operation in the ramjet and scramjet modes. It is desirable to delay this mixing process in the air-augmented mode of operation present during low speed flight. A model of the Strutjet device has been built and is undergoing test to investigate the mixing of the streams as a function of distance from the Strutjet exit plane during simulated low speed flight conditions. Cold flow testing of a 1/6 scale Strutjet model is underway and nearing completion. Planar Laser Induced Fluorescence (PLIF) diagnostic methods are being employed to observe the mixing of the turbine exhaust gas with the gases from both the primary rockets and the ingested air simulating low speed, air augmented operation of the RBCC. The ratio of the pressure in the turbine exhaust duct to that in the rocket nozzle wall at the point of their intersection is the independent variable in these experiments. Tests were accomplished at values of 1.0, 1.5 and 2.0 for this parameter. Qualitative results illustrate the development of the mixing zone from the exit plane of the model to a distance of about 10 rocket nozzle exit diameters downstream. These data show the mixing to be confined in the vertical plane for all cases, The lateral expansion is more pronounced at a pressure ratio of 1.0 and suggests that mixing with the ingested flow would be likely beginning at a distance of 7 nozzle exit diameters downstream of the nozzle exit plane

In vivo Spectroscopic and Imaging Studies of Photosensitizer in Photodynamic Therapy

Photodynamic Therapy (PDT) has emerged as a useful cancer treatment modality which utilizes a tumor localizing dye and activating light to selectively destroy neoplastic tissue. In an effort to understand the newly synthesized photosensitizers, we are studying them in a mouse tumor model grown on the dorsal side of the foot by in vivo magnetic resonance techniques. We have synthesized several photosensitizers which are specifically labeled with fluorine. Several coils appropriate for the tumor study by 19F NMR were designed and constructed for this project. The solenoid coil tunable to both 1Hand 19F nuclei was used to monitor the 19F labeled photosensitizer in the mouse foot tumor. An in vivo 19F NMR technique was used to study the retention of the photosensitizer over time in the tumor. We have used 31P NMR to study the outcome of PDT after using the new photosensitizer

Return to Play and Performance Following Anterior Cruciate Ligament Reconstruction in the National Women’s Soccer League

Background: The anterior cruciate ligament (ACL) is a commonly injured ligament in athletes, usually requiring ACL reconstruction (ACLR). Hypothesis/Purpose: To compare the return to play (RTP) and performance level of players following ACLR in the National Women’s Soccer League (NWSL). We hypothesized that there would be a high return to play rate following ACLR in the NWSL, but with a decrease in performance. Methods: NWSL players that underwent ACLR were identified by cross-referencing multiple online resources that were identified between the 2013 and 2020 seasons. Players were classified into the following positions: forward, defender, midfielder, and goalkeeper. The following RTP statistics were assessed: games played, games started, percentage of minutes played, and plus/minus net per 90 minutes. A sub-analysis was also performed to divide players based on median age (≤ 24 vs. \u3e25) at time of injury. Since a majority of these outcomes significantly violated the assumption of normality, continuous variables were reported using medians and interquartile ranges and nonparametric testing methods were used throughout the analysis. Results: A total of 30 NWSL athletes underwent ACLR between the 2013 and 2020 seasons. Midfielders constituted the highest percentage of injuries (n=11, 36.7%) followed by forwards (n=10, 33.3%). Of these 30 players, 27 returned to the NWSL post-injury, constituting a 90.0% RTP rate. The median RTP time was 12.1 months [interquartile range (IQR), 10.9 – 14.3 months]. There was a statistically significant decrease in the percentage of minutes played 1-year pre- and post-injury [median 87.9 (IQR: 80.7 – 90.6) vs. 25.1 (IQR: 16.3 – 57.2); p=0.031]. On age based sub-analysis, older players started significantly more games [median 12.0 (IQR: 3.8 – 18.5) vs. 3.0 (0.5 – 6.0); p=0.048)] and had a higher percentage of minutes played [median 63.0 (IQR: 18.8 – 77.3) vs. 14.9 (2.0 – 21.2); p=0.046] 1-year post injury compared to younger players. Conclusion: Our results support the hypothesis that there is a high RTP rate following ACLR in the NWSL. Following injury, players played in a lower percentage of minutes in the season they returned, with older players starting more games and playing a greater percentage of minutes compared to younger players

From Earth to Orbit: An assessment of transportation options

The report assesses the requirements, benefits, technological feasibility, and roles of Earth-to-Orbit transportation systems and options that could be developed in support of future national space programs. Transportation requirements, including those for Mission-to-Planet Earth, Space Station Freedom assembly and operation, human exploration of space, space science missions, and other major civil space missions are examined. These requirements are compared with existing, planned, and potential launch capabilities, including expendable launch vehicles (ELV's), the Space Shuttle, the National Launch System (NLS), and new launch options. In addition, the report examines propulsion systems in the context of various launch vehicles. These include the Advanced Solid Rocket Motor (ASRM), the Redesigned Solid Rocket Motor (RSRM), the Solid Rocket Motor Upgrade (SRMU), the Space Shuttle Main Engine (SSME), the Space Transportation Main Engine (STME), existing expendable launch vehicle engines, and liquid-oxygen/hydrocarbon engines. Consideration is given to systems that have been proposed to accomplish the national interests in relatively cost effective ways, with the recognition that safety and reliability contribute to cost-effectiveness. Related resources, including technology, propulsion test facilities, and manufacturing capabilities are also discussed